Indicating instrument



Aug. 23, 1938,. Av. E. CARBONARA Y INDICATING INSTRUMENT Filed Nov. 14, 1953 2 sheetssheet 1 il, W Q

IN V EN TOR. V/C TOI? E CARBON/IRA.

'A TTORNEY Aug. 23, 1938.

INDIGATING INSTRUMENT V. E. CARBONARA Filed NOV. 14, 1935 2 sheets-shee 2 ATTORNEY reuma Aug. 23,' 193sJ UNITE-D STATI-:s PATENT OFFICE Y :421.801 l 1 f Tltcafsit Bend, Ind.. a corporation ot Application VNovember 14, 1 933, Serial No. 697,991`

s claims. (ci. nsf-12s) The present invention relates tolindlcating instruments and, more particularly. to novel indi- :cating means therefor. t

The invention is particularly adapted to indicating instruments of the type having an indicating dial mounted in a casing for angular movement or rotation about a vertical axis and having a` top portion and a downwardly extending peripheral iiange on which are marked the scale v graduations of the dial, the latter being visible through a cover glass provided on one side of the casing. Such an instrument may bea compass, for example, in which the dial constitutes the compass card or it may be an automobile speedometer in which the dial is graduated to indicate speed in miles per hour.V The instrument may'be constructed and arranged for mounting on an provided the required indication or reading of i the instmment. ln the case ci the compass, this hair line or liibbei-"s marl; was usually in the orui of an upwardly projecting curved wire carried by the pivot post on which the -card of the compass was pivotally mounted. @sich an index Y ci' lubbers mark served its purpose satisfactorily when the instrument was viewed in the day time. When, however, illuminating means were provided for viewing the instrument atnight and the source was located above the index or lubbers marit, which is the desired location in order to provide suilclcient illumination ci the dial without undue glare, auch aorni ol index or lubbers line obviously could not be illuminated in'its entirety because the portion sloping inwardly toward the card and away from the direction. of

` the incoming light remained in the dark and 'only the upper part of the curved index, i. c.t the part nearer the source of illumination above the index was illuminated. Y

Accordingly, one of the objects of the present invention is to provide, in an indicating instrument of the class described, a novel index whereby, when a Asource of illumination is' provided which is located above the iront part of the dial and over the index, said index will be illuminated in its entirety.

v.Another object of the invention is to provide,

in an indicating instrument of Vthe above type, a

novel index cooperating with the dial of the instrument,4 which is so formed as to avoid parallax and to provide complete illumination of said index when the illuminating source is located therev above.

' 'I'he above and other objects and advantages of the invention will appear morei fully hereinafter from a consideration of the detailed description which follows, taken together with the accompanying drawings wherein one embodiment of the invention is illustrated.` It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not designed as a denitlon of the limits of the invention, reference being had for this purpose to the appended claims.

In the drawings wherein like reference characters refer to like parts throughout vthe several views:

. Eg. l is a vertical section of one form oi instrument embodying the novel index of the present invention; v

Fig. 2 is a iront view of the instrument shownA in Fig, l; and

Vlif'ig. 3 is a perspective view of the novel index embodying the invention. j

Referring to the drawings and, more particulariy, to liig. l, the instrument shown embodying the present invention is in the form of a magnetic compass of the liquid type wherein means' are provided iorilluminating the compass card of the compass from above as is the present general practice in the compass art. its illustrated, the compass comprises a casing il within which is contcincd o, compass card li plvotally mounted on a pivot post t in any suitable manner lmown. in the art. The card is substantially dat at the top as shown at l and is provided with a downwardly extending annular flange or rim t on which are marked the compass graduations 9. The card is provided with a pair of bar magnets lll suspended phragm device I6 is also provided at the real"` of 45 from the card by means of members il in order 40 A being desirable for the purpose of .the present the compass bowl for compensating for the expansion and contraction of the liquid I5*A due to temperature changes, the interior of said diaphragm device being in communication with the exterior of the bowl through an opening (not shown) provided in the bolt II by means of which said device is secured to the rear wall I8 of the compass bowl I.

Means are provided for illuminating the front portion oi' the compass card, i. e., the portion which is visible i'rom the front oi' the compass through the cover glass I2 and, in the form shown, comprise a lamp I8 positioned horizontally in an auxiliary compartment 2| formed by va removable drawer 2li which is adapted to be inserted into the auxiliary compartment by'means of a knob 22. The drawer 2li is so arranged that upon the insertion thereof into the compartment 2| the lamp I9 is adapted to be connected to an electrical circuit by means of a contact 23 carried by the drawer and a contact 24 carried by the compass bowl 4 in the compartment 2|. Connested to the contact 2l is a conductor 25 which leads to a receptacle 2l into which a plug 21 is adapted to be inserted. Light from the lamp i9 is introduced into the interior of the compass bowl l by means of a glass rod 28 carried by a threaded member 2l which is screwed into an opening 2l provided in the compass bowl I di.

rectly above the iront portion ot the compass card I. Thus, when the lamp Il is energized. light passes through the glass member 28 and onto the front portion of the compass card.

'lhe structure described thus far constitutes a compass of the type disclosed and claimed in a co-pending application of RaymondK. Stout, Serial 'No. 650,520, led January 6, 1933, and forms no part of the present invention except insofar as it is required that the illuminating means be above the compass card, such location invention. Cooperating with the compass card 5 is an index or lubbers mark 3| carried by an arm 32 secured to the member 33 carried by the pivot post I. In accordance with the present invention, this'index or lubbers mark 3| is so formed and arranged that when light is introduced into the compass bowl through the glass 2l from the lamp I0, said index member is illuminated in its entirety in order that it may be' completely visible at night thereby enabling reading of the compass card more readily. As illustrated, said index or lubbers mark 3| is constituted by a ilat strip projecting upwardly from the member 32 and in a vertical plane extendn ing radially from the periphery of the compass card so that the inner edge 3l is adjacent the card and the'outer edge 35 is visible from the front ot the compass through the vcover glass I2. The inner edge 3l is curved concavely with the concavity toward thef card so that the bottom of the-flange I falls substantially half way between the upper end'and the lowerend oi* the ilat stripl The outer Aedge Il is made to slope a curved wire. In view of the fact that, in accordance with. the present invention, the outer edge l5 is made to slope substantially continuousiy in the same direction, all parts thereof will receive light irom the source I9 through the glass member 28, thereby facilitating therreading oi the indication on the compass card 5. Also, because said index member is constituted by a ilat strip having sides of substantial surface, said sides are also illuminated, thereby enabling the viewing of the inner edge 34 more readily against the compass card and avoiding parallax which is always present when a hair line or wire is used. In other words, by virtue of the fiat nature of the member 3| the card may be viewed from either side of said index without giving an incorrect reading. It the index or lubbers mark were in the form of a hair line or wire, then ii.' the compass is viewed from the side the index will appear to be in alinement with a graduation farther from the index in a direction away from the observer. For example, l1 the index 3|, shown in Fig. 2, were a hair line instead of the fiat strip, then if the card were observed from the left oi Fig.'2 the index might appear to be in alignment with the graduation or 26 on the' compass card instead of with the graduation W. On the other hand, if the card were viewed from the right ot Fig. 2, the index would appear to be in alignment with graduations 28 or 29. With applicants novel index, such inaccuracy is not possible because the substantial width of the strip indicates to the observer that his line oi. vision is not in the plane of the index. He must, therefore, shift his line of vision until it isfin the plane of the strip at which time only the outer edge 25 will be visible.

There isy thus provided an indicating instru ment embodying a novel index member for cooperation with the dial ol the instrument Whereby, when the instrument is illuminated, said index member is illuminated inf its entirety thereby greatly facilitating the reading or the instru-.- ment and whereby, due to the novel form of said index member, parallax is avoided.

Although only one embodiment of the invention has been illustrated and described with reference to a magnetic compass oi the liquid type, it will be apparent to'those skilled in the art that the invention may be' adapted to instruments of other types such, for example, as an automobile speedometer having a, dial mounted for angular movement or rotation about a ver tical axis, i. e., the broad principles ot the invention may be adapted to any-instrument having a dial angularly movable or rotatable about a vertical axis and visible from the front of the instrument. Various changes in the form and relative arrangement of the parts may also be made without departing from the scope of Athe invention. Reference is, therefore, to be had to ,the appended claims for a definition ot the limits of the invention.

Whatisclaimed is:

,1. In an indicating instrument, an indicating .dial mounted for angular movement about a vvertical axis and having an annular rim with indicating marks thereon, and an index cooperating with said rim and comprising a substantially fiat member positioned adjacent'said rim in a vertical plane passing through said axis, the outerl edge of said member sloping substantially con-t tinuously outwardly of the dial from one end to the other of said member.

2. In an indicating instrument, an indicating positioned edgewlse with respect to said dial and thereof, and an index member cooperating with said dial and comprising a flat vertical member having its outer edge sloping substantially continuously outwardly from the top to the bottom, said member being so positioned that said edge may be illuminated in its entirety.v

3. In an indicating instrument, a'n indicating dial, means adjacent said dial for illuminating the same, and an index member cooperating with said dial and comprising a substantially iiat member positioned edgewise With'respect to'esaid dial and havingl one end near the illuminating means and having its outer edge sloping substantiallyv continuously outward of the dial from that end of said member which is near, the illuminating means whereby said outer edge is illuminated in its entirety. g

4. In a magnetic compass of the liquid type, a

`compass card having a downwardly extending annular flange with scale graduations thereon, l

and a lubbers mark comprising a flat member positioned vertically in a plane extending radially from the periphery of the card and having a concavely'curved inner edge adjacent to the periphery of said card with the upper `end of --said curved edge extending slightly over said card 'and the lower end of said curved edge extending under said card, the outer edge of. said flat member sloping outwardly from the top to the bottom v thereof.I 4

5. In a magnetic compass of the liquid type including a casing having a front opening closed 'by a cover glass, a compass card in said casing edge andthe upper end of the curved edge being substantially under said illuminating means and the lower end of said curved edge extending under sloping outwardly -from the top' to the bottom thereof whereby said outer edge is illuminated in its entirety.

VICTOR E. CARBONARA.

'said card, the outer edge of said at member 

